Atmospherics measurements in San Miguel, Argentina

Abstract

Measurements of VLF atmospherics taken atSan Miguel, Argentina, are presented. Results from one 13-year measurement period (1956-1969) as well as one 2-year interval (1971-1973) are used to document the morphology of the diurnal and annual variations in atmospherics activity at San Miguel. The atmospherics rates obtained during the second interval, which may be ordered according to arrival azimuth, show that most of the activity originates in thunderstorm cells located NE and NW of the observation station. Distance determinations from the dispersion of the atmospherics impulses, together with an estimate of the instrument's range, indicate that these activity cells lie primarily over the South American continent. Additional measurements of atmospherics activity taken in Berlin from 1971 to 1975 are also shown, from which a certain trend in the activity in the South American sector may be inferred. Both the Berlin and San Miguel records indicate a decline in atmospherics activity over the measurement period.